PROJECT SUMMARY/ABSTRACT African Americans and those of lower socioeconomic status (SES) are at disproportionate risk for hypertension- and cardiovascular-disease (CVD)-related mortality relative to whites and higher SES counterparts, respectively. These health disparities begin in early age and are difficult to mitigate in older adults. The long-term objective of the proposed work is to contribute to the understanding and subsequent reduction of race and SES-related health disparities in hypertension and CVD-related mortality. The proposed research aims to more precisely understand the proximal mechanisms by which unique social exposures disproportionately impacting certain populations influence various blood pressure parameters early in the lifespan and to determine which individuals are more at risk, thereby identifying modifiable factors that can inform both early intervention and primary prevention. Expanding on pilot work, the proposed research will utilize ecological momentary assessment (EMA) to assess race- and socioeconomic-based social factors as they manifest in daily life alongside simultaneously manifesting cognitive-emotional states and ambulatory blood pressure parameters. Assessment of these factors will allow for clearer identification of social adversity?s impact on early hypertension risk. The project specifically aims to expand on pilot work by: 1.) implementing a new way of explaining how social adversity impacts hypertension disparities through examining associations among intra-individual momentary race- and SES-based experiences, momentary cognitive- emotional reactions to them, and simultaneous blood pressure; 2.) investigating between-individual factors that influence momentary cardiovascular reactivity to race- and SES-based experiences; and 3.) investigating between-individual factors that influence nocturnal blood pressure dipping and short-term BP variability in a novel manner, i.e., by collapsing across momentary experiences occurring within the same time window as dipping and variability parameters. These aims will be accomplished by recruiting a community sample of 270 healthy African Americans between the ages of 18 and 30 to complete two periods of 2-day, 2-night ambulatory blood pressure monitoring with hourly cuff inflations during the daytime and nighttime alongside hourly EMA assessments of participants? experiences of discrimination, socioeconomic strain, and neighborhood strain during the waking hours. The two periods will be separated by one day of no monitoring. Participant sleep and wake times will be determined using an Actigraphy watch worn by participants throughout the monitoring periods and corroborated with participants? self-report. Participants will also complete self-report questionnaires to assess covariates and traditional blood pressure risk factors. This will be the first time that this research question is approached in this manner. Pilot work has already tested parts of the proposed methodology and demonstrated substantial promise.